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What is Free Evolution? Free evolution is the concept that natural processes can lead to the development of organisms over time. This includes the appearance and growth of new species. Many examples have been given of this, such as different varieties of fish called sticklebacks that can be found in salt or fresh water, and walking stick insect varieties that prefer specific host plants. These mostly reversible trait permutations however, are not able to explain fundamental changes in body plans. Evolution through Natural Selection The evolution of the myriad living creatures on Earth is an enigma that has intrigued scientists for many centuries. The most well-known explanation is that of Charles Darwin's natural selection process, an evolutionary process that occurs when better-adapted individuals survive and reproduce more effectively than those that are less well adapted. As time passes, the number of individuals who are well-adapted grows and eventually develops into an entirely new species. Natural selection is a cyclical process that involves the interaction of three elements: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within a species. Inheritance refers to the passing of a person's genetic characteristics to his or her offspring which includes both dominant and recessive alleles. Reproduction is the process of producing fertile, viable offspring, which includes both asexual and sexual methods. Natural selection only occurs when all the factors are in balance. If, for instance the dominant gene allele causes an organism reproduce and live longer than the recessive allele The dominant allele is more prevalent in a group. If the allele confers a negative advantage to survival or lowers the fertility of the population, it will be eliminated. The process is self-reinforcing, which means that an organism with an adaptive characteristic will live and reproduce much more than one with a maladaptive characteristic. The higher the level of fitness an organism has, measured by its ability reproduce and survive, is the greater number of offspring it produces. People with desirable characteristics, such as the long neck of Giraffes, or the bright white color patterns on male peacocks, are more likely than others to survive and reproduce, which will eventually lead to them becoming the majority. Natural selection is only an aspect of populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution, which states that animals acquire traits due to use or lack of use. If a giraffe expands its neck to reach prey and its neck gets longer, then the offspring will inherit this characteristic. The difference in neck size between generations will continue to increase until the giraffe becomes unable to reproduce with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles from a gene are randomly distributed in a population. At some point, one will attain fixation (become so common that it is unable to be eliminated by natural selection) and other alleles will fall to lower frequency. In extreme cases it can lead to a single allele dominance. Other alleles have been essentially eliminated and heterozygosity has decreased to zero. In a small population it could lead to the complete elimination of the recessive allele. This is known as the bottleneck effect and is typical of an evolution process that occurs when a large number individuals migrate to form a population. A phenotypic bottleneck can also occur when the survivors of a disaster like an outbreak or mass hunting event are confined to the same area. The remaining individuals will be largely homozygous for the dominant allele meaning that they all have the same phenotype, and thus have the same fitness traits. This could be caused by earthquakes, war or even plagues. Regardless of the cause the genetically distinct population that remains could be prone to genetic drift. Walsh, Lewens, and Ariew use a “purely outcome-oriented” definition of drift as any departure from the expected values of variations in fitness. They provide the famous case of twins who are genetically identical and share the same phenotype. However 에볼루션바카라 is struck by lightning and dies, whereas the other is able to reproduce. This kind of drift could be vital to the evolution of a species. But, it's not the only way to develop. The primary alternative is a process called natural selection, in which phenotypic variation in an individual is maintained through mutation and migration. Stephens argues there is a significant difference between treating the phenomenon of drift as an actual cause or force, and treating other causes like migration and selection as causes and forces. He argues that a causal mechanism account of drift allows us to distinguish it from other forces, and this distinction is vital. He also argues that drift is a directional force: that is it tends to eliminate heterozygosity. He also claims that it also has a magnitude, that is determined by the size of the population. Evolution by Lamarckism Biology students in high school are frequently introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution, commonly referred to as “Lamarckism, states that simple organisms transform into more complex organisms taking on traits that result from the organism's use and misuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher leaves in the trees. This process would cause giraffes to pass on their longer necks to their offspring, who then become taller. Lamarck Lamarck, a French Zoologist from France, presented a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. According Lamarck, living organisms evolved from inanimate material by a series of gradual steps. Lamarck was not the first to suggest that this might be the case but the general consensus is that he was the one giving the subject his first comprehensive and thorough treatment. The dominant story is that Charles Darwin's theory on natural selection and Lamarckism fought in the 19th Century. Darwinism ultimately prevailed which led to what biologists call the Modern Synthesis. The theory argues the possibility that acquired traits can be inherited and instead argues that organisms evolve through the action of environmental factors, like natural selection. Although Lamarck endorsed the idea of inheritance by acquired characters, and his contemporaries also offered a few words about this idea, it was never an integral part of any of their evolutionary theories. This is partly due to the fact that it was never validated scientifically. It's been over 200 year since Lamarck's birth, and in the age genomics, there is a growing evidence-based body of evidence to support the heritability-acquired characteristics. It is sometimes referred to as “neo-Lamarckism” or more often epigenetic inheritance. It is a version of evolution that is as valid as the more well-known Neo-Darwinian theory. Evolution through the process of adaptation One of the most popular misconceptions about evolution is that it is driven by a sort of struggle to survive. This view is inaccurate and ignores other forces driving evolution. The fight for survival is more accurately described as a struggle to survive in a specific environment. This may include not just other organisms, but also the physical environment. To understand how evolution functions it is important to understand what is adaptation. It refers to a specific characteristic that allows an organism to live and reproduce within its environment. It could be a physical feature, like fur or feathers. Or it can be a behavior trait such as moving towards shade during hot weather or escaping the cold at night. The capacity of an organism to draw energy from its surroundings and interact with other organisms as well as their physical environments is essential to its survival. The organism must have the right genes to create offspring, and must be able to access enough food and other resources. The organism should be able to reproduce itself at an amount that is appropriate for its specific niche. These elements, along with gene flow and mutations can cause changes in the proportion of different alleles within a population’s gene pool. Over time, this change in allele frequencies could result in the development of new traits and ultimately new species. Many of the features that we admire about animals and plants are adaptations, such as lung or gills for removing oxygen from the air, fur or feathers for insulation long legs to run away from predators and camouflage for hiding. However, a thorough understanding of adaptation requires a keen eye to the distinction between physiological and behavioral characteristics. Physiological adaptations like the thick fur or gills are physical traits, while behavioral adaptations, such as the desire to find friends or to move to the shade during hot weather, are not. It is also important to remember that a lack of planning does not make an adaptation. Inability to think about the effects of a behavior even if it seems to be rational, may make it inflexible.